/Engine/Source/Runtime/CoreUObject/Public/UObject/PackageResourceManager.h
OpenMappedHandleToPackage that takes a PackageSegment
[IMappedFileHandle](API\Runtime\Core\Async\IMappedFileHandle) * OpenMappedHandleToPackage ( const [FPackagePath](API\Runtime\CoreUObject\Misc\FPackagePath) & PackagePath, EPackageSegment PackageSegment, [FPackagePath](API\Runtime\CoreUObject\Misc\FPackagePath) * OutUpdatedPath )